During Italy part 1 and 2 Ray and Robert don't speak a whole lot of Italian. However during episode S02E14 "Mia Famiglia" when aunt Sarina visits they appear to be fluent.
Marie states her birthday is coming up and she planned a two week summer vacation in Italy; however, other episodes indicate her birthday is in December.
When Ray takes a bath, his hair starts out neatly slicked back, then is suddenly mussed up.
(at around 15 mins) Stefania tells Robert she will show him Rome and Il Lago di Bracciano (Lake Bracciano). However both of the Italy episodes were shot mostly in the town of Anguillara Sabazia, on the Lake Bracciano. Aunt Coletta's house is at the edge of Lake Bracciano, and the lake is in the background for most of the episode, such as when the camera zooms out as Ray and Debra are on the balcony, and the scenes at the gelateria's outside tables.